Educators especially: I encourage you to use anything you find here that is useful to your mission educating people about Earth science. E-mail me if it would help to have a larger or higher-resolution version of any of the images.

Upper 10 is apparently a “Sprite”-esque lemon-lime soda, discontinued in America but still being marketed abroad. But that wasn’t what got me jazzed, of course. Look more closely…

That is a lovely little conchoidal fracture, and it’s so exquisite because it preserves not only the concentric “ribs” that are typical of conchoidal fractures, but also delicate little traces of plumose structure. Note that the conchoidal “ribs” are parallel to the advancing joint front (leading edge of the fracture), and the plumes are perpendicular to the joint front.

Here’s an annotated copy to make this more explicit:

The same pattern can be observed in a second fracture, this one located within the glass (not on the surface):